Display panel and mobile terminal

ABSTRACT

A display panel comprising a light guide plate; a main light source configured to emit light from a first lateral surface of the light guide plate in a first direction; a sub-light source configured to emit light from a second lateral surface vertical to the first lateral surface of the light guide plate in a second direction perpendicular to the first direction; and a liquid crystal panel provided in a front surface of the light guide plate and configured to output image information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of copending U.S. patent applicationSer. No. 14/720,200, filed on May 22, 2015, which claims priority toKorean Patent Application No. 10-2015-0028947, filed in the Republic ofKorea on Mar. 2, 2015, all of which are hereby expressly incorporated byreference into the present application.

BACKGROUND OF THE DISCLOSURE

Field of the Disclosure

Embodiments of the present disclosure relate to a display panel whichcan display an image on a predetermined area of a display unit and amobile terminal including the same.

Background of the Disclosure

Terminals may be generally classified as mobile/portable terminals orstationary terminals. Mobile terminals may also be classified ashandheld terminals or vehicle mounted terminals. Mobile terminals havebecome increasingly more functional. Examples of such functions includedata and voice communications, capturing images and video via a camera,recording audio, playing music files via a speaker system, anddisplaying images and video on a display. Some mobile terminals includeadditional functionality which supports game playing, while otherterminals are configured as multimedia players. More recently, mobileterminals have been configured to receive broadcast and multicastsignals which permit viewing of content such as videos and televisionprograms.

As such functions become more diversified, the mobile terminal cansupport more complicated functions such as capturing images or video,reproducing music or video files, playing games, receiving broadcastsignals, and the like. By comprehensively and collectively implementingsuch functions, the mobile terminal may be embodied in the form of amultimedia player or device. As the multimedia function is strengthened,a display unit of a mobile terminal is enlarged and an image quality isenhanced in a form of high resolution. Accordingly, a significant amountof electricity is consumed in driving the display of the mobileterminal.

As the display unit is active longer, the power consumption isincreased. However, when some area of the related art display unit isactivated, an actual overall screen is activated and the other area,except the image displaying area, displays a black color and there islittle difference in the actual amount of the consumed power, whichincreases the power consumption.

SUMMARY OF THE DISCLOSURE

Accordingly, an object of the present disclosure is to address theabove-noted and other problems.

Another object of the present disclosure is to provide a mobile terminalwhich minimizes the power consumed by the display unit, when the displayunit displays an image in a predetermined area thereof.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein, thepresent invention provides in one aspect a display panel including alight guide plate; a main light source configured to emit light from afirst lateral surface of the light guide plate in a first direction; asub-light source configured to emit light from a second lateral surfacevertical to the first lateral surface of the light guide plate in asecond direction perpendicular to the first direction; and a liquidcrystal panel provided in a front surface of the light guide plate andconfigured to output image information.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by illustration only, since various changes and modificationswithin the spirit and scope of the invention will become apparent tothose skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given herein below and the accompanying drawings,which are given by illustration only, and thus are not limitative of thepresent invention, and wherein:

FIG. 1A is a block diagram of a mobile terminal according to anembodiment the present disclosure.

FIGS. 1B and 1C are conceptual views of one example of the mobileterminal, viewed from different directions;

FIG. 2 is an exploded perspective diagram illustrating a display panelaccording to an embodiment of the present disclosure;

FIG. 3 is a front view illustrating a light guide plate and a lightsource provided in the display panel according to an embodiment of thepresent disclosure;

FIGS. 4 and 5 are diagrams illustrating an IC circuit controlling a mainlight source and a sub light source according to an embodiment of thepresent disclosure;

FIG. 6 is a front view illustrating a liquid crystal panel of thedisplay panel according to an embodiment of the present disclosure;

FIG. 7 is a front view illustrating various embodiments of a front topend of the mobile terminal according to an embodiment of the presentdisclosure; and

FIGS. 8 and 9 are graphs illustrating sizes of signals applied to theliquid crystal panel of the mobile terminal according to an embodimentof the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Description will now be given in detail according to embodimentsdisclosed herein, with reference to the accompanying drawings. For thesake of brief description with reference to the drawings, the same orequivalent components may be provided with the same reference numbers,and description thereof will not be repeated. In general, a suffix suchas “module” and “unit” may be used to refer to elements or components.Use of such a suffix herein is merely intended to facilitate descriptionof the specification, and the suffix itself is not intended to give anyspecial meaning or function.

The accompanying drawings are used to help easily understand varioustechnical features and the embodiments presented herein are not limitedby the accompanying drawings. As such, the present disclosure should beconstrued to extend to any alterations, equivalents and substitutes inaddition to those which are particularly set out in the accompanyingdrawings.

Although the terms first, second, etc. may be used herein to describevarious elements, these elements should not be limited by these terms.These terms are generally only used to distinguish one element fromanother. When an element is referred to as being “connected with”another element, the element can be directly connected with the otherelement or intervening elements may also be present. In contrast, whenan element is referred to as being “directly connected with” anotherelement, there are no intervening elements present.

A singular representation may include a plural representation unless itrepresents a definitely different meaning from the context. Terms suchas “include” or “has” are used herein and indicate an existence ofseveral components, functions or steps, disclosed in the specification,and it is also understood that greater or fewer components, functions,or steps may likewise be utilized.

Mobile terminals presented herein may be implemented using a variety ofdifferent types of terminals. Examples of such terminals includecellular phones, smart phones, user equipment, laptop computers, digitalbroadcast terminals, personal digital assistants (PDAs), portablemultimedia players (PMPs), navigators, portable computers (PCs), slatePCs, tablet PCs, ultra books, wearable devices (for example, smartwatches, smart glasses, head mounted displays (HMDs)), and the like. Byway of non-limiting example only, further description will be made withreference to particular types of mobile terminals. However, suchteachings apply equally to other types of terminals, such as those typesnoted above. In addition, these teachings may also be applied tostationary terminals such as digital TV, desktop computers, and thelike.

Reference is now made to FIGS. 1A-1C, where FIG. 1A is a block diagramof a mobile terminal 100 according to an embodiment of the presentdisclosure, and FIGS. 1B and 1C are conceptual views of one example ofthe mobile terminal, viewed from different directions. The mobileterminal 100 is shown having components such as a wireless communicationunit 110, an input unit 120, a sensing unit 140, an output unit 150, aninterface unit 160, a memory 170, a controller 180, and a power supplyunit 190. Implementing all of the illustrated components is not arequirement, and that greater or fewer components may alternatively beimplemented.

Referring now to FIG. 1A, the mobile terminal 100 is shown havingwireless communication unit 110 configured with several commonlyimplemented components. For instance, the wireless communication unit110 typically includes one or more components which permit wirelesscommunication between the mobile terminal 100 and a wirelesscommunication system or network within which the mobile terminal islocated.

The wireless communication unit 110 typically includes one or moremodules which permit communications such as wireless communicationsbetween the mobile terminal 100 and a wireless communication system,communications between the mobile terminal 100 and another mobileterminal, communications between the mobile terminal 100 and an externalserver. Further, the wireless communication unit 110 typically includesone or more modules which connect the mobile terminal 100 to one or morenetworks. To facilitate such communications, the wireless communicationunit 110 includes one or more of a broadcast receiving module 111, amobile communication module 112, a wireless Internet module 113, ashort-range communication module 114, and a location information module115.

The input unit 120 includes a camera 121 for obtaining images or video,a microphone 122, which is one type of audio input device for inputtingan audio signal, and a user input unit 123 (for example, a touch key, apush key, a mechanical key, a soft key, and the like) for allowing auser to input information. Data (for example, audio, video, image, andthe like) is obtained by the input unit 120 and may be analyzed andprocessed by controller 180 according to device parameters, usercommands, and combinations thereof.

The sensing unit 140 is typically implemented using one or more sensorsconfigured to sense internal information of the mobile terminal, thesurrounding environment of the mobile terminal, user information, andthe like. For example, in FIG. 1A, the sensing unit 140 is shown havinga proximity sensor 141 and an illumination sensor 142.

If desired, the sensing unit 140 may alternatively or additionallyinclude other types of sensors or devices, such as a touch sensor, anacceleration sensor, a magnetic sensor, a G-sensor, a gyroscope sensor,a motion sensor, an RGB sensor, an infrared (IR) sensor, a finger scansensor, a ultrasonic sensor, an optical sensor (for example, camera121), a microphone 122, a battery gauge, an environment sensor (forexample, a barometer, a hygrometer, a thermometer, a radiation detectionsensor, a thermal sensor, and a gas sensor, among others), and achemical sensor (for example, an electronic nose, a health care sensor,a biometric sensor, and the like), to name a few. The mobile terminal100 may be configured to utilize information obtained from sensing unit140, and in particular, information obtained from one or more sensors ofthe sensing unit 140, and combinations thereof.

The output unit 150 is typically configured to output various types ofinformation, such as audio, video, tactile output, and the like. Theoutput unit 150 is shown having a display unit 151, an audio outputmodule 152, a haptic module 153, and an optical output module 154. Thedisplay unit 151 may have an inter-layered structure or an integratedstructure with a touch sensor in order to facilitate a touch screen. Thetouch screen may provide an output interface between the mobile terminal100 and a user, as well as function as the user input unit 123 whichprovides an input interface between the mobile terminal 100 and theuser.

The interface unit 160 serves as an interface with various types ofexternal devices that can be coupled to the mobile terminal 100. Theinterface unit 160, for example, may include any of wired or wirelessports, external power supply ports, wired or wireless data ports, memorycard ports, ports for connecting a device having an identificationmodule, audio input/output (I/O) ports, video I/O ports, earphone ports,and the like. In some cases, the mobile terminal 100 may performassorted control functions associated with a connected external device,in response to the external device being connected to the interface unit160.

The memory 170 is typically implemented to store data to support variousfunctions or features of the mobile terminal 100. For instance, thememory 170 may be configured to store application programs executed inthe mobile terminal 100, data or instructions for operations of themobile terminal 100, and the like. Some of these application programsmay be downloaded from an external server via wireless communication.Other application programs may be installed within the mobile terminal100 at time of manufacturing or shipping, which is typically the casefor basic functions of the mobile terminal 100 (for example, receiving acall, placing a call, receiving a message, sending a message, and thelike). It is common for application programs to be stored in the memory170, installed in the mobile terminal 100, and executed by thecontroller 180 to perform an operation (or function) for the mobileterminal 100.

The controller 180 typically functions to control overall operation ofthe mobile terminal 100, in addition to the operations associated withthe application programs. The controller 180 can provide or processinformation or functions appropriate for a user by processing signals,data, information and the like, which are input or output by the variouscomponents depicted in FIG. 1A, or activating application programsstored in the memory 170. As one example, the controller 180 controlssome or all of the components illustrated in FIGS. 1A-1C according tothe execution of an application program that have been stored in thememory 170.

The power supply unit 190 can be configured to receive external power orprovide internal power in order to supply appropriate power required foroperating elements and components included in the mobile terminal 100.The power supply unit 190 may include a battery, and the battery may beconfigured to be embedded in the terminal body, or configured to bedetachable from the terminal body.

Referring now to FIGS. 1B and 1C, the mobile terminal 100 is describedwith reference to a bar-type terminal body. However, the mobile terminal100 may alternatively be implemented in any of a variety of differentconfigurations. Examples of such configurations include watch-type,clip-type, glasses-type, or as a folder-type, flip-type, slide-type,swing-type, and swivel-type in which two and more bodies are combinedwith each other in a relatively movable manner, and combinationsthereof. Discussion herein will often relate to a particular type ofmobile terminal (for example, bar-type, watch-type, glasses-type, andthe like). However, such teachings with regard to a particular type ofmobile terminal will generally apply to other types of mobile terminalsas well.

The mobile terminal 100 will generally include a case (for example,frame, housing, cover, and the like) forming the appearance of theterminal. In this embodiment, the case is formed using a front case 101and a rear case 102. Various electronic components are incorporated intoa space formed between the front case 101 and the rear case 102. Atleast one middle case may be additionally positioned between the frontcase 101 and the rear case 102. A rear case 103 can also be provided.

The display unit 151 is shown located on the front side of the terminalbody to output information. A window of the display unit 151 may bemounted to the front case 101 to form the front surface of the terminalbody together with the front case 101. In some embodiments, electroniccomponents may also be mounted to the rear case 102. Examples of suchelectronic components include a detachable battery 191, anidentification module, a memory card, and the like. Rear cover 103 isshown covering the electronic components, and this cover may bedetachably coupled to the rear case 102. Therefore, when the rear cover103 is detached from the rear case 102, the electronic componentsmounted to the rear case 102 are externally exposed.

As illustrated, when the rear cover 103 is coupled to the rear case 102,a side surface of the rear case 102 is partially exposed. In some cases,upon the coupling, the rear case 102 may also be completely shielded bythe rear cover 103. In some embodiments, the rear cover 103 may includean opening for externally exposing a camera 121 b or an audio outputmodule 152 b.

The cases 101, 102, 103 may be formed by injection-molding syntheticresin or may be formed of a metal, for example, stainless steel (STS),aluminum (Al), titanium (Ti), or the like. As an alternative to theexample in which the plurality of cases form an inner space foraccommodating components, the mobile terminal 100 may be configured suchthat one case forms the inner space. In this example, a mobile terminal100 having a uni-body is formed so synthetic resin or metal extends froma side surface to a rear surface.

If desired, the mobile terminal 100 may include a waterproofing unit forpreventing introduction of water into the terminal body. For example,the waterproofing unit may include a waterproofing member which islocated between the window and the front case 101, between the frontcase 101 and the rear case 102, or between the rear case 102 and therear cover 103, to hermetically seal an inner space when those cases arecoupled.

FIGS. 1B and 1C depict certain components as arranged on the mobileterminal. However, alternative arrangements are possible and within theteachings of the instant disclosure. Some components may be omitted orrearranged. For example, the first manipulation unit 123 a may belocated on another surface of the terminal body, and the second audiooutput module 152 b may be located on the side surface of the terminalbody.

The display unit 151 outputs information processed in the mobileterminal 100. The display unit 151 may be implemented using one or moresuitable display devices. Examples of such suitable display devicesinclude a liquid crystal display (LCD), a thin film transistor-liquidcrystal display (TFT-LCD), an organic light emitting diode (OLED), aflexible display, a 3-dimensional (3D) display, an e-ink display, andcombinations thereof.

The display unit 151 may be implemented using two display devices, whichcan implement the same or different display technology. For instance, aplurality of the display units 151 may be arranged on one side, eitherspaced apart from each other, or these devices may be integrated, orthese devices may be arranged on different surfaces. The display unit151 may also include a touch sensor which senses a touch input receivedat the display unit. When a touch is input to the display unit 151, thetouch sensor may be configured to sense this touch and the controller180, for example, may generate a control command or other signalcorresponding to the touch. The content which is input in the touchingmanner may be a text or numerical value, or a menu item which can beindicated or designated in various modes.

The touch sensor may be configured in a form of a film having a touchpattern, disposed between the window and a display on a rear surface ofthe window, or a metal wire which is patterned directly on the rearsurface of the window. Alternatively, the touch sensor may be integrallyformed with the display. For example, the touch sensor may be disposedon a substrate of the display or within the display.

The display unit 151 may also form a touch screen together with thetouch sensor. Here, the touch screen may serve as the user input unit123. Therefore, the touch screen can replace at least some of thefunctions of the first manipulation unit 123 a. The display unit 151according to an embodiment of the present disclosure may be divided intotwo areas arranged in parallel along a first direction. The two areasmay be independently controlled and one of the two areas may beselectively activated if necessary, so that power consumption can bereduced. In FIG. 1B, the display unit 151 includes a display panel 200having first and second areas 201 and 202.

For example, the first area 201 may be an area outputting imageinformation and the second area 202 may be an area displaying a statusbar for displaying a status of the mobile terminal. When the user is notusing the mobile terminal 100, the first area 201 may be in an OFFstatus and the second area 202 may be in an ON status where the user cancheck a status of the mobile terminal or a new event even when not usingthe mobile terminal.

The second area 202 shown in the drawing may have a smaller width thanthe first area 201 or the first and second areas 202 may have the samewidth. In the latter case, a larger area may be utilized as a displayarea. However, a bezel located in an edge area (a non-display areaformed in an edge area around a display area of the display panel)disadvantageously increases. Further, the first audio output module 152a may be implemented in the form of a speaker to output voice audio,alarm sounds, multimedia audio reproduction, and the like.

The window of the display unit 151 will typically include an aperture topermit audio generated by the first audio output module 152 a to pass.One alternative is to allow audio to be released along an assembly gapbetween the structural bodies (for example, a gap between the window andthe front case 101). In this instance, a hole independently formed tooutput audio sounds may not be seen or is otherwise hidden in terms ofappearance, thereby further simplifying the appearance and manufacturingof the mobile terminal 100.

The optical output module can be configured to output light forindicating an event generation. Examples of such events include amessage reception, a call signal reception, a missed call, an alarm, aschedule notice, an email reception, information reception through anapplication, and the like. When a user has checked a generated event,the controller 180 can control the optical output unit to stop the lightoutput. In addition, the first camera 121 a can process image framessuch as still or moving images obtained by the image sensor in a capturemode or a video call mode. The processed image frames can then bedisplayed on the display unit 151 or stored in the memory 170.

Further, the first and second manipulation units 123 a and 123 b areexamples of the user input unit 123, which may be manipulated by a userto provide input to the mobile terminal 100. The first and secondmanipulation units 123 a and 123 b may also be commonly referred to as amanipulating portion, and may employ any tactile method that allows theuser to perform manipulation such as touch, push, scroll, or the like.The first and second manipulation units 123 a and 123 b may also employany non-tactile method that allows the user to perform manipulation suchas proximity touch, hovering, or the like.

FIG. 1B illustrates the first manipulation unit 123 a as a touch key,but possible alternatives include a mechanical key, a push key, a touchkey, and combinations thereof. Input received at the first and secondmanipulation units 123 a and 123 b may be used in various ways. Forexample, the first manipulation unit 123 a may be used by the user toprovide an input to a menu, home key, cancel, search, or the like, andthe second manipulation unit 123 b may be used by the user to provide aninput to control a volume level being output from the first or secondaudio output modules 152 a or 152 b, to switch to a touch recognitionmode of the display unit 151, or the like.

As another example of the user input unit 123, a rear input unit may belocated on the rear surface of the terminal body. The rear input unitcan be manipulated by a user to provide input to the mobile terminal100. The input may be used in a variety of different ways. For example,the rear input unit may be used by the user to provide an input forpower on/off, start, end, scroll, control volume level being output fromthe first or second audio output modules 152 a or 152 b, switch to atouch recognition mode of the display unit 151, and the like. The rearinput unit may be configured to permit touch input, a push input, orcombinations thereof.

The rear input unit may be located to overlap the display unit 151 ofthe front side in a thickness direction of the terminal body. As oneexample, the rear input unit may be located on an upper end portion ofthe rear side of the terminal body such that a user can easilymanipulate it using a forefinger when the user grabs the terminal bodywith one hand. Alternatively, the rear input unit can be positioned atmost any location of the rear side of the terminal body.

Embodiments that include the rear input unit may implement some or allof the functionality of the first manipulation unit 123 a in the rearinput unit. As such, in situations where the first manipulation unit 123a is omitted from the front side, the display unit 151 can have a largerscreen. As a further alternative, the mobile terminal 100 may include afinger scan sensor which scans a user's fingerprint. The controller 180can then use fingerprint information sensed by the finger scan sensor aspart of an authentication procedure. The finger scan sensor may also beinstalled in the display unit 151 or implemented in the user input unit123.

The microphone 122 is shown located at an end of the mobile terminal100, but other locations are possible. If desired, multiple microphonesmay be implemented, with such an arrangement permitting the receiving ofstereo sounds. The interface unit 160 serves as a path allowing themobile terminal 100 to interface with external devices. For example, theinterface unit 160 may include one or more of a connection terminal forconnecting to another device (for example, an earphone, an externalspeaker, or the like), a port for near field communication (for example,an Infrared Data Association (IrDA) port, a Bluetooth port, a wirelessLAN port, and the like), or a power supply terminal for supplying powerto the mobile terminal 100. The interface unit 160 may be implemented inthe form of a socket for accommodating an external card, such asSubscriber Identification Module (SIM), User Identity Module (UIM), or amemory card for information storage.

In addition, the second camera 121 b is shown located at the rear sideof the terminal body and includes an image capturing direction that issubstantially opposite to the image capturing direction of the firstcamera unit 121 a. If desired, the second camera 121 b may alternativelybe located at other locations, or made to be moveable, in order to havea different image capturing direction from that which is shown.

The second camera 121 b can include a plurality of lenses arranged alongat least one line. The plurality of lenses may also be arranged in amatrix configuration. The cameras may be referred to as an “arraycamera.” When the second camera 121 b is implemented as an array camera,images may be captured in various manners using the plurality of lensesand images with better qualities.

As shown in FIG. 1C, a flash 124 is shown adjacent to the second camera121 b. When an image of a subject is captured with the camera 121 b, theflash 124 may illuminate the subject. As shown in FIG. 1C, the secondaudio output module 152 b can be located on the terminal body. Thesecond audio output module 152 b may implement stereophonic soundfunctions in conjunction with the first audio output module 152 a, andmay be also used for implementing a speaker phone mode for callcommunication.

At least one antenna for wireless communication may be located on theterminal body. The antenna may be installed in the terminal body orformed by the case. For example, an antenna which configures a part ofthe broadcast receiving module 111 may be retractable into the terminalbody. Alternatively, an antenna may be formed using a film attached toan inner surface of the rear cover 103, or a case that includes aconductive material.

The power supply unit 190 for supplying power to the mobile terminal 100may include a battery 191, which is mounted in the terminal body ordetachably coupled to an outside of the terminal body. The battery 191can receive power via a power source cable connected to the interfaceunit 160. Also, the battery 191 can be recharged in a wireless mannerusing a wireless charger. Wireless charging may be implemented bymagnetic induction or electromagnetic resonance.

The rear cover 103 is shown coupled to the rear case 102 for shieldingthe battery 191, to prevent separation of the battery 191, and toprotect the battery 191 from an external impact or from foreignmaterial. When the battery 191 is detachable from the terminal body, therear case 103 may be detachably coupled to the rear case 102. Anaccessory for protecting an appearance or assisting or extending thefunctions of the mobile terminal 100 can also be provided on the mobileterminal 100. As one example of an accessory, a cover or pouch forcovering or accommodating at least one surface of the mobile terminal100 may be provided. The cover or pouch may cooperate with the displayunit 151 to extend the function of the mobile terminal 100. Anotherexample of the accessory is a touch pen for assisting or extending atouch input to a touch screen

Next, FIG. 2 is an exploded perspective illustrating a display panel 200according to an embodiment of the present disclosure. Referring to FIG.2, the display panel 200 may include a liquid crystal panel 210 and abacklight unit 220. The backlight unit 220 is configured to emit lightprovided from light sources 227 and 228 forwardly to a front surface ofthe display panel 200 uniformly. The backlight unit 220 includes lightsources 227 and 228, a light guide plate 225, polarizing plate (prismsheets) 221, 222, a diffusion plate 223 and a reflector 226.

The light sources 227 and 228 are arranged in a lateral surface of thelight guide plate 225 to supply the light to the lateral surface. Thelight guide plate 225 diffuses the light supplied by the light sourcestherein, using total reflection. In more detail, the total reflection isa characteristic activated in the light guide plate 225 only when anincident angle of the light is less than a critical angle. The lightincident on the lateral surface is incident at a critical angle or moreand then diffused while totally reflected in the light guide plate 225.Further, when the incident angle of the light is bent at the less thanthe critical angle, the light is emitted from the light guide plate 225.

Further, uniform unevenness is formed in a surface of the light guideplate to emit the light incident from the lateral surface to the liquidcrystal panel 210 forwardly. For example, a semi-spherical-shapedprojection is formed in a rear surface of the light guide plate 225 toguide the light to be diffused and emitted forwardly. The density, thesize and the like of the unevenness can be adjusted to emit theuniformly diffused light to the front surface. In addition, thereflector 226 may be provided under the rear surface of the light guideplate 225 and re-reflects the light escaping from rear surface of thelight guide plate 225 toward the front surface, to prevent loss of thelight.

The diffusion plate 223 is disposed in front of the front surface of thelight guide plate 225 and diffuses the light emitted from the lightguide plate 225 more uniformly, to make the light a surface-lightsource. In addition, two prism sheets 221 and 222 may be disposed on atop surface of the diffusion plate 223 and bend the light spread in alateral direction to a forward direction, to secure brightness in aforward direction.

In more detail, FIG. 3 is a front view illustrating the light guideplate 225 and the light sources 227 and 228 provided in the displaypanel 200. In FIG. 3, a main light source 227, a sub-light source 228and the light guide plate 225 are shown. Different from a related artbacklight unit including light sources supplied in one direction, thebacklight unit 220 according to an embodiment of the present disclosureincludes light sources supplied in two directions.

In particular, main light sources 227 arranged along a first lateralsurface 225 a of the light guide plate 225 supply light to an entirearea of the light guide plate 225 uniformly. The plurality of the mainlight sources 227 may be spaced apart a predetermined distance from thefirst lateral surface 225 a. A second lateral surface 225 b of the lightguide plate 225 is provided in a perpendicular direction with respect tothe first lateral surface 225 a and the sub-light source 228 can supplylight to an end opposite to the first lateral surface where the mainlight sources are arranged.

In addition, the light guide plate 225 may be rectangular-shaped. Asshown in FIG. 3, the light guide plate 225 may have a dent 224 dentformed in one corner of the light guide plate 225. One of lateralsurfaces forming the dent is vertical to the first lateral surface 225 aand the lateral surface is the second lateral surface 225 b to have thelight incident emitted from the sub-light source 228 thereon. Further,the main light sources 227 and the sub-light source 228 can be drivenindependently. When the main light sources 227 are off, only thesub-light source 228 can be controlled to be on.

Next, FIGS. 4 and 5 are diagrams illustrating an IC circuit configuredto control the main light sources 227 and the sub-light source 228. Inthe IC circuit shown in FIG. 4, one backlight IC 186 controls the mainlight sources 227 and the sub-light source 228. In the IC circuit shownin FIG. 5, two backlight ICs 186 control the main light sources 227 andthe sub-light source 228.

In more detail, the power supply unit 190 supplies the electric power toboth of the main light sources 228 and the sub-light source 228. Noiseis eliminated, using a bypass booster 187, so that a stable power can besupplied. When the backlight IC 186 applies a signal to the lightsources 227 and 228, light can be emitted from the light sources 227 and228. In this instance, the backlight IC 186 can adjust a brightness ofLEDs 186 a arranged in each of the light sources up to 2000 levels ormore. An optimal brightness of the backlight to see a correspondingimage may be determined based on information from low data of an imagetransmitted from a drive IC 215 of the liquid crystal panel 210 (CABC:Content Adaptive Brightness Control).

When using one backlight unit IC 186 shown in FIG. 4, one LED channel isfurther used so as control the sub-light source 228, instead of usingthe related art backlight IC 186. As shown in FIG. 5, an auxiliarybacklight IC 186′ may be further provided to control only the sub-lightsource 228. Further, the plurality of the main light sources 227 may beprovided in parallel, adjacent to the first lateral surface 225 a, tosupply the light to the entire area of the light guide plate 225. On thecontrary, one or two sub-light sources fewer than the main light sources227 can be provided to supply light to a predetermined area of the lightguide plate 225.

In addition, the light guide plate 225 shown in FIG. 3 (a) may beintegrally formed as one body and it may be supplied with light not onlyby the main light sources 227 but also by the sub-light source 228.Alternatively, the light guide plate 225 shown in FIG. 3 (b) may includea first light guide plate 2251 configured to emit the light supplied bythe main light sources 227 toward the front surface of the display panel200 and a second light guide plate 2252 configured to emit the lightsupplied by the sub-light source 228 toward the front surface of thedisplay panel 200.

When the light guide plate is the one body type shown in FIG. 3 (a), themain light sources 227 can supply light to the second area 202 as wellas the first area 201. Accordingly, the sub-light source 228 need not beon advantageously, when the main light sources 227 are on. Also, animage continuously displayed on the second area 202 and the first area201 can be output.

Meanwhile, when the light guide plate is the divided type including thefirst light guide plate 2251 and the second light guide plate 2252 shownin FIG. 3 (b), the light supplied by the main light sources 227 can betransmitted only to the first area 201 through the first light guideplate 2251 and the light supplied by the sub-light source 228 can betransmitted only to the second area 202 through the second light guideplate 2252.

In addition, the sub-light source 228 is driven to output information onthe second area 202, even when the main light sources 227 are on. Wheninformation is displayed only on the second area 202, the light does notneed to be supplied to the first area 201 and an image having a highbrightness can be displayed, using a small number of light sources (LEDlamps).

Further, the main light sources 227 and the sub-light source 228 arecombinedly connected to a main printed circuit board or independentlyconnected to the main printed circuit board. The controller 180 can thusindependently control the main light sources 227 and the sub-lightsource 228.

As the sub-light source 228 is arranged in the second lateral surface225 b, a bezel of the second lateral surface 225 b could increase. For alarge display unit, the large size of the bezel increased by thesub-light source 228 is not significant compared to the overall size.However, the size of the bezel is a quite important factor indetermining the overall size of a small sized mobile terminal. In otherwords, a first corner opposite to the second lateral surface 225 b wherethe sub-light source 228 is dented and thus prevents the increase of thelateral-direction bezel. That is, the sub-light source 228 is formed inthe dent 224 so that the bezel can be prevented from increasing towardthe lateral surface.

In the embodiment shown in FIG. 3 (b), the width of the second lightguide plate 2252 can be equal to the width of the first light guide 2251when the width of the first area 201 is equal to the width of the secondarea 202. When the dent 224 is provided in first corner of the lightguide plate 225, the width of the second light guide plate 2252 can besmaller than the width of second light guide plate 2252.

Next, FIG. 6 is a front view illustrating the liquid crystal panel 210of the display panel 200 according to an embodiment of the presentdisclosure. The size of the liquid crystal panel 210 is similar to thesize of the light guide plate 225. When the dent 224 is provided in thelight guide plate 225, a dent 217 may be formed in a corner of theliquid crystal panel 210, corresponding to the dent 224 of the lightguide plate 225.

While the light guide plate 225 is divided into the portioncorresponding to the first area 201 and the other portion correspondingto the second area 202, the liquid crystal panel 210 may have a unitedportion and be controlled by one drive IC. The drive IC can be connectedwith the liquid crystal panel 210 via a main printed circuit board and aflexible printed circuit board 216, so that it can apply the electricpower to each pixel according to an image signal transmitted from themain printed circuit board and adjust liquid crystal arrangement.

Further, the liquid crystal panel 210 selectively applies the power topixels to change the arrangement of the liquid crystal and outputsdifferent colors for pixels to provide an image. As shown in FIG. 2, theliquid crystal panel 210 includes a color filter layer 212 and a thinfilm transistor layer 213. The color filter layer 212 includes a colorfilter and a common electrode. In addition, the color filter has a redfilter, a green filter and a blue filter for pixels. The thin filmtransistor layer 213 may include a plurality of thin film transistorsprovided corresponding to colors of the color filters, respectively.

When the power is applied to the thin film transistors, the liquidcrystal arrangement of a corresponding pixel is changed and light isselectively penetrated to output a color according to image informationfor each pixel. A gate voltage and a data voltage are also applied tothe thin film transistor. When a data voltage larger than a gate voltageis applied, the liquid crystal arrangement of the corresponding pixel ischanged.

In more detail, liquid crystal is injected between the color filterlayer 212 and the thin film transistor layer 213 and polarizing films211 and 214 are disposed on an outer surface of the color filter layer212 and an outer surface of the thin film transistor layer,respectively, and the light may be aligned forwardly. Further, thedisplay panel 200 including the liquid crystal panel 210 and thebacklight unit 220 can be arranged in the front surface of the mobileterminal 100 as shown in FIG. 1B, to output information according to thecontrol of the controller 180 provided in the mobile terminal 100.

Next, FIG. 7 is a front view illustrating various embodiments of a fronttop end of the mobile terminal 100 according to an embodiment of thepresent disclosure. When the display panel 200 includes the dent 224,the sub-light source 228 is located in the dent 224. Also, the camera121, the proximity sensor 141, the illumination sensor 142 and areceiver hole for outputting a sound of the audio output module 152 canbe arranged in the dent 224.

As the camera 121, the proximity sensor 141 and the illumination sensor142 are provided in the dent 224, the size of the bezel provided in anupper end portion of the display panel 200 can be reduced. Further, thedent 224 may be rectangular as shown in FIG. 7 (a), have an inclinedsurface as shown in FIG. 7 (b), or have a curved surface as shown inFIG. 7 (c).

In addition, a status bar may be arranged in the second area 202 todisplay a status of the mobile terminal 100. Also, in the second area202 may be displayed icons 1516 indicating a remaining amount ofbattery, presence of new messages, a communication status, presence ofWIFI access, presence of Bluetooth connection and the like. Simpleinformation such as time and weather can also be output in the secondarea 202.

When an icon 1516 indicating presence of a new event generated in themobile terminal is displayed on the status bar, the user can drag theicon 1516 to the first area 201 to implement a function corresponding tothe icon or to check specific information associated with thecorresponding event. As shown in FIG. 7 (b), the user's name or aspecific paragraph set by the user can be output or a new notice event(e.g., schedule notice and new message reception) may be provided to theuser. The user can also set diverse contents of the status bar, whilecontents of the status bar are not fixed. Whenever an event isgenerated, different information can be output.

In addition, when user authentication not using the display panel 200,for example, iris recognition or fingerprint recognition is performed,user authentication can be guided, only using the second area 202 of thedisplay panel 200. For example, the user's distance and location isguided as shown in FIG. 7 (c) and the user authentication for the mobileterminal 100 can then be implemented. Further, the user can adjust thesize of the status bar output in the second area 202 to a deformed shapeshown in FIG. 7 (b) and FIG. 7 (c) as well as an existing rectangularshaped status bar shown in FIG. 7 (a).

When using the display panel 200 according to an embodiment of thepresent disclosure, the first area 201 and the second area 202 can bedriven independently. In particular, the liquid crystal panel 210 can bedriven in a first mode configured to output information in one of thefirst area 201 and the second area 202 and a second mode configured tooutput information only in the second area 202, and not in the firstarea 201.

Also, the liquid crystal panel 210 can be driven in a third modeconfigured not to output information in the first area 201 and thesecond area 202 and a fourth mode configured to output information onlyin the first area 201, and not in the second area 202. In the firstmode, the display panel is used typically. That is, the main lightsources 227 and the sub-light source 228 are driven and the entire thinfilm transistors of the liquid crystal panel 210 are driven.

However, when the user puts the mobile terminal 100 on a desk, and isnot using the mobile terminal 100, the display panel 200 can be drivenin the second mode. Then, when the user touches the display panel 200 orpresses a button in the third mode where the display panel 200 is off,the third mode is converted into the second mode and only the secondarea of the display panel 200 is activated.

In the second mode, the display panel 200 of the first area 201 is notused and the main light sources 227 configured to supply light to thefirst area 201 are not driven. Considering that the light sources use70˜80% of the power to drive the main light sources 227, the driving ofthe main light sources 227 is stopped and only the sub-light source 228fewer than the main light sources 227 are driven. Accordingly, the powerconsumed by the display panel 200 can be reduced by 70%.

Next, FIGS. 8 and 9 are graphs illustrating signals applied to theliquid crystal panel 210. In particular, FIG. 8 is a graph illustratingvoltages of a gate signal, multiplexer signal (MUX) and a data signal inthe first mode, and FIG. 9 is a graph illustrating a gate signal, amultiplexer (MUX) signal and a data signal in the second mode.

As the entire screen is used in the first mode, the gate, multiplexerand data signal have to be transmitted to the first area 201 and thesecond area 202. Further, the gate signal is used to determine athreshold voltage of each thin film transistor. Only when a data voltagewhich is a voltage applied to the gate signal or more has to be applied,the liquid crystal arrangement is changed and an image is output.

In addition, the multiplexer may be arranged between the drive IC andeach of the thin film transistors. Thus, the gate signal and the datasignal which will be transmitted to each of the transistors may be toone multiplexer, so that the number of signal lines can be reduced.Further, the signals transmitted from the drive IC through themultiplexer can be re-distributed sequentially and then there-distributed signals can be supplied to the transistors.

In addition, the gate signal includes a gate clock and a sheet-resistor,and the sheet-resistor receives a clock and transmits data to the nextgate. The data signal is configured to drive the liquid crystal panelbased on color information of each pixel. Further, a larger voltage isapplied to the data signal than the gate signal when liquid crystalarrangement has to be changed and the light supplied by the backlightunit can be transmitted forwardly.

When the display panel 200 is driven in the second mode configured toactivate only the second area 202, with the first area 201 being off, asshown in FIG. 9, a data signal corresponding to the first area may notbe transmitted and the data signal of the first area 201 may be 0V. Withno data signal and outputting no image, the multiplexer does not need todistribute the signals and clocking of the signals. Further, themultiplexer can control a value of the applied voltage to be 0V.

Meanwhile, the gate signal has to calculate a gate clock to besynchronized with the location of each thin film transistor. Inparticular, the gate signal has to be clocked at preset intervals evenin the first area 201 where no data is output. As no data signal isapplied actually in the first area 201, the voltage of the gate signalis not important and the size of the gate signal is set to be small. Forexample, the voltage of the gate signal has to be ±9V in the second area202 where the liquid crystal arrangement is changed according to thedata signal and the voltage of the gate signal can be reduced to be ±5Vin the first area 201 where no gate signal is output.

As mentioned above, according to an embodiment of the presentdisclosure, the power consumption can be minimized when only thepredetermined area of the display unit is activated. Accordingly, hoursof battery use can be increased. Further, the sub-light source isarranged in the dent 224 for the second area 202 configured to output animage independently. Accordingly, the size of the mobile terminal can beprevented from increasing toward the lateral surface of the mobileterminal.

Moreover, needed and useful information can be displayed rapidly in thesecond area 202, which is always activated. Thus, the user does not haveto activate the display unit 151 to check the time or presence of a newevent. Accordingly, the user's convenience is enhanced.

The present invention encompasses various modifications to each of theexamples and embodiments discussed herein. According to the invention,one or more features described above in one embodiment or example can beequally applied to another embodiment or example described above. Thefeatures of one or more embodiments or examples described above can becombined into each of the embodiments or examples described above. Anyfull or partial combination of one or more embodiment or examples of theinvention is also part of the invention.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are therefore intendedto be embraced by the appended claims.

What is claimed is:
 1. A mobile terminal comprising: a wirelesscommunication unit configured to provide wireless communication; a lightguide plate; light sources emitting light to one or more lateralsurfaces of the light guide plate; a liquid crystal panel including afirst area provided in a portion of the liquid crystal panel and asecond area provided in another portion of the liquid crystal panel, andconfigured to output information selectively passing light provided fromthe light guide plate; and a controller configured to drive the liquidcrystal panel in one of a first mode configured to display informationin the first area and the second area, and a second mode configured todisplay information only in the second area and not display informationin the first area, wherein the liquid crystal panel comprises aplurality of thin film transistors configured to change an arrangementof liquid crystal in response to a gate voltage and a data voltage, andwherein the controller is further configured to: control the datavoltage applied to the thin film transistor of the first area in thesecond mode to be 0 (zero) V, and control the gate voltage applied tothe thin film transistor of the first area in the second mode to begreater than 0V and smaller than the gate voltage applied to the thinfilm transistor of the second area.
 2. The mobile terminal of claim 1,further comprising: a drive IC configured to transmit a signal to theplurality of the thin film transistors based on a control signaltransmitted from the controller; and a multiplexer (MUX) providedbetween the drive IC and the plurality of the thin film transistors todistribute a signal to the plurality of the thin film transistors,wherein the controller is further configured to restrict the driving ofthe multiplexer to distribute the signal to the thin film transistor ofthe first area in the second mode.
 3. The mobile terminal of claim 1,wherein in the second mode, the gate voltage applied to the thin filmtransistor of the second area is 9V or more and the gate voltage appliedto the thin film transistor of the first area is greater than 0V andequal to or less than 5V.
 4. The mobile terminal of claim 1, wherein thelight sources comprise: a main light source configured to emit lightfrom a first lateral surface of the light guide plate in a firstdirection; and a sub-light source configured to emit light from a secondlateral surface vertical to the first lateral surface of the light guideplate in a second direction perpendicular to the first direction, andwherein the controller is further configured to drive only the sub-lightsource and not the main light source in the second mode.
 5. The mobileterminal of claim 4, wherein the light guide plate has a dent in onecorner of the light guide plate, and wherein the sub-light source isarranged in the dent.
 6. The mobile terminal of claim 5, wherein theliquid crystal panel comprises a dent corresponding to the dent of thelight guide plate.
 7. The mobile terminal of claim 5, further comprisingone or more of a camera module, a proximity and illumination sensormodule and a receiver hole configured to output sound of an audio outputmodule arranged in the dent of the light guide plate.
 8. The mobileterminal of claim 4, wherein the light guide plate comprises: a firstlight guide plate provided in a portion with respect to a firstdirection, the first light guide plate including the first lateralsurface; and a second light guide plate provided in the other portionwith respect to the first direction, the second light guide plateincluding the second lateral surface, and wherein the main light sourceemits light to the first light guide plate and the sub-light sourceemits light to the second light guide plate.
 9. The mobile terminal ofclaim 8, a width of the first light guide plate in the second directionis larger than a width of the second light guide plate in the seconddirection.
 10. The mobile terminal of claim 1, wherein the indicationinformation includes an icon indicating a status of the mobile terminal,and wherein the controller is further configured to execute a functioncorresponding to the icon, in response to the icon being dragged fromthe second area to the first area.
 11. The mobile terminal of claim 1,wherein the controller is further configured to display a guide imagefor unlocking the mobile terminal in the second area.
 12. The mobileterminal of claim 1, wherein the controller is further configured todisplay updated indication information in the second area in response toa new event on the mobile terminal.